<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
		*{
			padding: 0;
			margin: 0;
		}
		li{
			list-style-type: none;
		}
		.first>li{
			display: inline-block;
			width: 150px;
			position: relative;/*子绝父相*/
		}
		
		.first ul{
			display: none;
			position: absolute;
			left: 50px;
		}	
		.first>li:hover>ul{
			display: block;
			
		}
		
		</style>
	</head>
	<body>
		<ul class="first">
			<li >一级菜单
				<ul >
					<li>二级菜单</li>
					<li>二级菜单</li>
					<li>二级菜单</li>
					<li>二级菜单</li>
				</ul>
			</li>
			<li>一级菜单
				<ul>
					<li>二级菜单</li>
					<li>二级菜单</li>
					<li>二级菜单</li>
					<li>二级菜单</li>
				</ul>
			</li>
			<li>一级菜单
				<ul>
					<li>二级菜单</li>
					<li>二级菜单</li>
					<li>二级菜单</li>
					<li>二级菜单</li>
				</ul>
			</li>
		</ul>
		
	</body>
</html>
